Coffee grounds have been considered as garbage produced when manufacturing coffee beverage for a long time, and are discarded by soil burial without proper use. Currently, TW Patent No: I338729 discloses a textile application of coffee grounds. Coffee grounds contain oils. To improve textile process yield, it is needed to remove organic components in coffee grounds. However, secondary waste (ex: coffee oil) is produced during the removing process and can not be effectively used. This waste influences the environment and takes much cost after treating process. Therefore, recovery and utilization of waste coffee oil are relative important under a rise in environmental issues.
Biomass is generally obtained from natural products, including directly use of natural plants (such as corn, palm, soy, etc.), or reuse of waste natural plants (such as coffee grounds, rice straw, waste wood, etc.). Utilizing waste of natural plant will not cause food conflict. This patent technique described above has disclosed the usage of coffee grounds for textile application. If coffee oil contained in coffee grounds can be recycled and reused to reduce generation of second waste, it will be helpful to reduce environmental impact and regarded as a kind of biomass.
In general, functional fabrics reaching waterproof and moisture permeability are made by coating of colloidal polymeric material or laminating of hydrophilicity film. Currently, the film with function of waterproof and moisture permeability is made by chemicals such as polyurethane which is artificially synthesized by petrochemicals. Polyurethane is a liner blocked copolymer formed by reacting polyester or polyether polyol with diisocyanate and small molecule of chain extender. It contains two kinds of segment: one is a soft segment which is consisted of polyester, polyether or polyamine diol and diisocyanate. The other one is a hard segment which is consisted of diisocyanate (aromatic compounds or aliphatic compounds) and chain extender.
In view of that raw materials for making polyurethane are obtained by petroleum oil, developing natural polyol to replace the petroleum product becomes desirable for both sustainable and environmental reasons. In PU manufacturing, vegetable oil from corn and soybean can be replacement for polyols. Patent as U.S. Pat. Nos. 7,786,239, 7,674,925, 7,696,370 or 6,433,121 uses soy oil to produce natural polyol. Due to the content of unsaturated fatty acid in soy oil is up to 84%, higher than the content of coffee oil (54.6%), hydroxy value (OH value) of the polyol produced from coffee oil is lower than that of the polyol produced from soy oil. The lower OH value will affect reactivity of subsequent PU synthesis and result in incomplete import of coffee polyol to PU main chain.
Therefore, how to use natural waste to reach the goal of re-use of resources is most needed to be studied.